Boiler construction



. Filed May '7; 1932 Patented Apr. 16, 1935 UNITED STATES PATENT OFFICEApplication May 7, 1

'7 Claims.

This invention relates to a boiler construction and has specialreference to the formation of a combustion arch for a boilerconstruction.

More particularly this invention has reference 5 to a fire-brick tile soconstructed as to form a combustion arch when a plurality thereof arearranged in order, each of the tiles comprising preferably a bodyvportion lying in a plane inclined with respect to an upper surfacethereof.

Combustion arches have been employed in many boilers for the purpose ofobtaining more complete combustion of the fuel and the volatile productsof combustion thereof as a measure of economy and to prevent theissuance of an undue amount of smoke to pollute the air. A combustionarch is located substantially centrally of the masonry housingsupporting the boiler and depends from the boiler in a spaced relationto the floor and to a bridge wall adjacent the fire box. Generally thevolatile products of combustion circulate through the boilerconstruction by passing rearwardly from the fire box over the bridgewall and thence under the combustion arch and upwardly and forwardlythrough the ilues of the boiler to the stack.

In my copending application Serial Number 596,261, filed March 2, 1932,a combustion arch is shown which is constructed in a manner to retardthe flow of the volatile products of combustion given off from the fueland to provide in effect a trap therefor. By retarding these products,ample opportunity is afforded for the burning thereof in the fire box.The copending application shows a combustion arch built up of aplurality of the usual fire-brick courses having a facing of the usualnre-brick masonry to provide a pocket inclined in the direction of thebridge Wall.

vIn the usualvboiler constructions the combustion arches, when used, arebuilt up in courses of the usual re brick although the inclined surfacesextend in a direction away from the bridge walls and fire boxes.

The present invention contemplates the provision of a combustion archfrom a plurality of tile preformed to meet either of the aboverequirements. The tile may be formed of the usual rebrick ingredientswith a. body portion inclined with respect to the upper surface thereof.Tongues and grooves are preferably provided on opposite sides thereoffor assisting in locking adjacent blocks together, the sides convergingwhen a continuous arcuate top surface is desired across a course oftile.

It may be readily seen that the tile may ac- 932, Serial N0. 609,856

comxnodate a condition wherein the arch extends in a direction towardthe fire box and, by reversing the tile, may also accommodate acondition wherein the arch extends in a direction away from the firebox. The tiles being preformed in the manner above described permit of avery simple and inexpensive installation thereof in a boilerconstruction.

One of the objects of this invention is to provide a combustion archwhich is comparatively inexpensive to install.

Another object of this invention is to provide a combustion arch whichis simple and durable.

A further object of this invention is to provide a tile for use in theformation of a combustion arch having a face surface inclined withrespect to an upper substantially nat surface.

Other objects and advantages will hereinafter be more fully pointed outand for a more cornplete understanding of the characteristic features ofthis invention reference may be had to the following description whenread together with the accompanying drawing, in which latter:

Figure 1 is a central vertical longitudinal sectional view showing aboiler construction incorporating the features of this invention;

Fig. 2 is an enlarged transverse sectional View taken on the line 2-2 ofFig. 1;

Fig. 3 is a perspective view of a side skew or one of the end tilemembers incorporated in the above construction; and

Fig. 4 is a perspective View of one of the intermediate tile members.

Referring now more particularly to the drawing, the construction thereinshown comprises a housing formed preferably of masonry of the usual typefor supporting a steam boiler II),4 the forward end of the boilerresting on the front end of the housing and the rear end being supportedby a central post IIla of a comparatively small diameter to notmaterially interfere with the flow of gases through the combustioncharnber. The front end II of the housing has the usual fire box openingI2 and the ash pit opening I3 for permitting access, respectively, tothe fire box and ash pit.

A bridge wall I4, preferably of the same material as that of thehousing, is disposed within the housing and extends preferably upwardlyfrom the base thereof to a spaced distance from the boiler Ill forsubdividing the housing into a fire box portion I5 and a combustionchamber I6, the fire box and combustion chamber having communicationtherebetween by reason of the spaced relation between the top of thebridge wall and the lower periphery of the boiler.

A combustion arch I'I is disposed in the combustion chamber adjacent thelower periphery of the boiler and extends downwardly therefrom toterminate in a spaced relation with the floor of the housing. Thecombustion arch of the form illustrated particularly in the drawing isso designed as to provide a pocket for trapping a portion of thevolatile products of combustion given off from the fuel in the nre boxand for retarding the flow of such products in the circulation thereoffrom the fuel box to the combustion chamber.

The volatile products of combustion are preferably circulated throughthe housing from the re box over the top of the bridge wall I4 and underthe combustion arch Il to the rear of the combustion chamber, whereafterthey are directed upwardly by reason of their striking the end wall I8of the housing to be directed through the iues of the boiler I0 to thestack I9. In this manner of circulation an effective transfer of heat isobtained to the water in the boiler. Unburned volatile products ofcombustion are insured ample opportunity to be burned, the passage ofthe products of combustion being somewhat retarded in their flow by thepeculiar shape given to the combustion arch. In order to prevent anyundue pressure being built up in the pocket formed by the arch, suitablevents 20 are provided adjacent the upper end thereof to permit of theescape of some of the products therethrough.

In order to assist in effecting a complete combustion within the boilerconstruction, incendiary means may be provided at one or more points inthe housing for burning the unburned products of combustion during thecirculation thereof. A plurality of nozzles 2I may be provided in thefront end II of the housing for blowing a combustible steam mixturedownwardly acrosss the flre box above the fuel therein in the directionof the bridge wall. 'I'he nozzle is connected by a suitable conduit to asource of supply of steam and fuel. As an auxiliary incendiary means, aplurality of nozzles 22 may be disposed in the housing for burning thevolatile products of combustion in the combustion chamber and, as shownin the drawing, such a nozzle or nozzles are provided in the rear wallIl of the housing.

The nozzles 2 I and 22 are connected to a pipe line 23 for connectionwith a source of steam supply, preferably from the boiler I0 if itshould happen to be a high preure boiler, or for connection with coilswhich are given to that specinc purpose coming into contact with theheat from the fire box. Some of the steam from the source of supply isby-passed into a tank containing a combustible compound, and by reasonof the compression thus produced in the tank, some of the combustiblemixture is forced back into the main supply line to become vaporizedwith the steam and emitted from the nozzles 2| and 22. Further, the pipeline 23 is enclosed by a conduit for directing pre-heated air to thenozzle from a point remote from the boiler. All of this latterconstruction is shown and described more particularly in my copendingapplication above noted.

The combustion arch of the present invention contemplates the formationthereof from a plurality of tiles 25 preferably formed of the sameingredients as the usual fire-brick and arranged in a single course,each of the tiles having preferably a flat upper surface 2B forsupporting the ordinary fire-brick 21. The front face 28 of the tile isinclined over a substantial distance thereof relatively to the flatupper surface thereof and, as shown in full lines in Fig. 1 of thedrawing, the inclination extends in a direction toward the bridge wallI4. The rear surface 29 of the tile 25 is likewise preferably formed atan inclination and extends preferably parallel with the front surface28.

A lower projecting portion 30 is preferably formed at the bottom of theinclination so as to permit of its being rested readily on a temporarysupport (not shown) which latter is removed after the arch is assembled.Also a ledge 3| is formed in the rear portion of the tile for thepurpose of permitting the upper portion of the tile to rest on atemporary support during the installation of the arch, which support isalso removed after the tiles are set. However, the formation of aprojecting lug 30 and a ledge 3i are not necessary to the essentialworking of the construction, but are desirable when the tiles areassembled in the boiler construction.

The side edges of the tile preferably converge in order that the uppersurfaces 26 thereof form a continuous arc. This construction ispreferable for strength, although it is to be understood that the archmay be formed straight by the provision of substantially parallel sides,and whether straight or converged edges are employed it is preferable toprovide an interlocking means in the form of ridges 32 on one edge anddepressions 33 on the other edge for interlocking adjacent tiles whenassembled. A suitable binder may be employed between the tiles althoughit is not deemed essential. Of course, the construction may be modified,if desired, by the provision of a. ridge and a groove on each side or byvariations thereof.

For convenience in handling, a separate tile section or so-called sideskew 34 is shown that may be set in the wall of the housing, the tileconforming more or less to the shape of the edge of the intermediatetile members, although having a square end portion for fittingvertically and horizontally in the wall of the housing in order to avoidfitting of portions of bricks in the housing wall. One of the side skews34 is illustrated very clearly in Fig. 3 of the drawing and it isbelieved needs no further description, it being provided with eitherridges or grooves to fit the adjacent intermediate tiles for the endsupport thereof.

The fire-brick 21 disposed above the combustion arch 25 are set in theusual manner by providing courses of the ordinary fire-brick to meet thelower periphery of the boiler I0.

In lieu of the inclined surface 28 extending in the direction of thebridge Wall I4, the same may be reversed and extended in a directionaway from the bridge wall, since, in some instances, it is desirable toform a combustion arch of this character. Such a construction is shownin dotted lines in Fig. l oi' the drawing, the tiles being merelyreversed in position.

As a result of this invention, the fabrication of the combustion arch isvery much simplified and materially reduced in cost of materials and incost of labor in that but a single course of fire brick tile may beemployed to effect an inclined arch, whereas, in previous constructions,so far as applicant is aware, the inclination is had by the building upof courses of bricks at the desired inclination at a substantialincrease in cost of labor and material.

While but a single embodiment of this invention is herein shown anddescribed, it is to be understood that various modications thereof willbe apparent to those skilled in the art without departing from thespirit and scope of this invention and, therefore, the same is to belimited only to the scope of the prior art and the appended claims.

I claim:

1. The combination with a boiler construction comprising a housinghaving a ilre box and a combustion chamber, of an arch in saidcombustion chamber formed of a plurality of tiles arranged in a singlecourse, each of said tiles having an inclined surface extending in thedirection of said fire box.

2. 'I'he combination with a boiler construction comprising a housinghaving a re box and a combustion chamber, of an arch in said combustionchamber formed of a plurality of tiles set side by side, the front facesof each of said tiles being inclined toward said fire box.

3. The combination with a boiler construction comprising a housinghaving a fire box and a combustion chamber, of an arch in saidcombustion chamber formed of a plurality of tiles set side by side, oneside of each of said tiles having projecting portions fory engagingrecessed portions on the other side of adjacent tiles, the front facesof each of said tiles being inclined in a direction toward said firebox.

4. The combination with a boiler construction comprising a housinghaving a re box and a combustion chamber, of an arch in said combustionchamber formed of a plurality of tiles set side by side in a singlecourse, each of said tiles having a flat upper surface for supportingfirebrick and a face surface inclined with respect to said uppersurface.

5. The combination with a boiler construction comprising a housinghaving a fire box and a combustion chamber, of an arch in saidcombustion chamber formed of a plurality of tiles set side by side in asingle course, each of said tiles having a flat upper surface forsupporting rebrick and front and rear surfaces inclined With respect tosaid upper surface.

6. The combination with a boiler construction comprising a housinghaving a fire box and a combustion chamber, of an arch in saidcombustion chamber formed of a plurality of tiles set side by side in asingle course, each of said tiles having a flat upper surface forsupporting rebrick and a front face inclined in a direction toward saidfire box.

7. The combination with a boiler construction comprising a housinghaving a nre box and a combustion chamber, of an arch in said combustionchamber formed of a plurality of tiles having front faces inclined inthe direction of said fire box.

FREDERICK H. SCHALK.

